Viewer

ABSTRACT

A picture viewer of the type using an interchangeable carrier having a circular row of transparency frames, the removable carrier being rotatable in a cavity in a housing having a viewing aperture. A circle of lateral projections is located on the wheel, one projection being associated with each frame. A plunger carries a pair of arms projecting into the cavity parallel to the wheel. One arm carries wedge means engagable between a pair of the projections and the other arm carries pusher means bearable against a projection. On depressing the plunger the wedge means is disengaged from the projections and the pusher means rotates the wheel.

.Eune4,1974

waited States Patent [191 Shasha 3,592,536 7/1971 Licitis et 40/70 A X VHEWER [76] Inventor:

Fahim Jacob Shasha, 49 Chipwood Crescent, Willowdale 425, Ontario, Canada Primary Examiner.loseph S. Reich Assistant ExaminerJ. H. Wolff [57] ABSTRACT A picture viewer of the type using an interchangeable [22] Filed: May 2, 1973 [21] Appl. No.: 356,312

carrier having a circular row of transparency frames, the removable carrier being rotatable in a cavity in a housing having a viewing aperture. A circle of lateral projections is located on the wheel, one projection being associated with each frame. A plunger carries a pair of arms projecting into the cavity parallel to the wheel. One arm carries wedge means engagable between a pair of the projections and the other arm car- 06 9 Hm ,R 036 A 9A 1 C H O .7 ""15 m A WW4 w W K "30 7 m M m W "n /O mm w es Mme ..e9 8 L .f o dW SLMA UhF mm 55 References Cited UNITED STATES PATENTS ries pusher means bearable against a projection. On

depressing the plunger the wedge means is disengaged X AX WNH

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VIEWER This invention relates to a picture viewer of the type which uses interchangeable carrier wheels with a number of transparencies located annularly around the periphery of the disc of each wheel.

Picture viewers commonly in use have a replaceable carrier wheel rotatable in a housing. The wheel carries a number of transparencies in an annular series of frames around its periphery, each frame being registrable with an aperture in the housing. The transparencies are selectively viewed by turning the wheel and looking through the housing aperture. To register each frame selectively with the aperture, while having the wheel replaceable, requires additional mechanism which increases the cost of production of a low-cost device.

It is an object of the present invention to provide-a picture viewer, of the type having a replaceable transparency wheel. which is of simple construction.

An example embodiment of the invention is shown in the accompanying drawings in which:

FIG. I is an exploded perspective view of a viewer according to the invention;

FIG. 2 is a cross-sectional view taken along line 22 of FIG. 1;

FIG. 3 is a front view in elevation of the carrier wheel and the advancement mechanism in a position of rest and locking the carrier wheel;

FIG. 4 is a view similar to FIG. 3 showing the advancement mechanism in fully depressed position having advanced the carrier wheel one frame;

FIG. 5 is a view again similar to FIG. 3 showing the advancement mechanism released and moving back into a position of rest;

FIG. 6 is a fragmentary side view of the pusher arm in relation to the carrier wheel pegs in the position of rest shown in FIG. 3;

FIG. 7 is a view, similar to FIG. 6, of the pusher arm in the position shown in FIG. 4; and

FIG. 8 is a view, again similar to FIG. 6, of the pusher arm in the position shown in FIG. 5.

The embodiment of the viewer shown in the drawings consists of a housing 10 having a pair of opposed walls 12 and I4 spaced apart by a spacer 16 with a shoulder 17 defining a semi-circular cavity 18 of slightly more than 180. A pair of spring loaded bullet detents 20 are located more than 180 apart and adjacent each end of shoulder 17 to removably retain a carrier wheel 22 forced laterally past the detents into cavity 18. Wheel 22 comprises a flat disc 28 having a circumferential rim 29. A plurality of transverse ridges 24 on shoulder 17 of cavity 18, together with detents 20, aids in allowing wheels 22 to be rotated coaxially on the axis 26 of the cavity when the wheel is located in the cavity with rim 29 bearing against detents 20 and ridges 24. It will be appreciated that the lateral gap in cavity 18 is slightly greater than the diameter of wheel 22 for entrance of the wheel into the cavity.

Carrier wheel 22 has a plurality of photographic transparencies 30 which are located in a circular row of equally spaced apertures 32 adjacent rim 29 of disc 28 and held in place by an apertured plate 34 superimposed on the disc to form frames 35. A plurality of projections in the shape of pegs 36 are equally spaced to form a ring outstanding laterally from wheel 22 and concentric with the row of transparencies 30 the ring being of smaller diameter than the row of frames 35 and one peg being located adjacent each frame.

A pair of aligned viewing apertures 38 are located in walls 12 and I4 of housing I0 to intersect frames 35 when carrier wheel 22 is located in cavity 18 of the housing. One of the two apertures 38 carries a lens 40. One side of each wall 12 and 14 has an indent 42 enabling carrier wheel 22 to have a greater exposed area projecting from one side of housing 10 when located in the housing.

Spacer 16 also defines a rectangular recess 44 in the bottom end of housing 10 to receive a rectangular plunger 46 for slidable movement in the recess. A pair of arms 48 and 50 project upwardly from plunger 46 into cavity I8. Arm 48 lies along the diameter of wheel 22 and arm 50 lies tangential to the row of pegs 36. Arm 48 is rigid and carries at its free end wedge means comprising a block 52 having a main portion 54 of a width greater than the distance between any two of pegs 36 and a wedge portion 56 converging towards plunger 46. Arm 50 is flexible in a direction normal to the plane of carrier wheel 22 and carries at its free end pusher means comprising a block 58 having a flat bearing face 60 and a slide face 62 sloping towards the arm in the direction of plunger 46. Arms 48 and 50 are slidable in a pair of parallel slots 64 in wall 14 of housing It) and arm 50 is additionally flexible in its slot in the direction of wall I4. A weak compression spring 66 in shoulder 16 bears against plunger 46 to urge the plunger in a direction away from wheel 22. When plunger 46 is in a position of rest, as seen in FIG. 3, body portion 54 of wedge block 52 lies between two of pegs 36 remote from the plunger and pusher block 58 lies between another two of pegs 36 disposed about from the wedge block.

The operation of the example embodiment is shown in FIGS. 3 to 8 of the drawings. FIG. 3 shows the device in a position of rest with spring 66 urging plunger 46 away from carrier wheel 22 and the plunger being held within the recess by wedge block 52 of arm 48 bearing against two pegs 36d and 36e, with pusher block 58 of arm 50 resting against two pegs 36a and 36b as seen in FIG. 6. The position of wedge block 52 between two pegs 36d and 36e also prevents carrier wheel 22 from rotating about axis 26, and at the same time pegs 36 are arranged to position a frame 35 and its transparency 30 in line with apertures 38 of housing 10, to be seen through lens 40.

To rotate carrier wheel 22 to view the next transparency 30 through lens 40, plunger 46 is pushed upwardly as seen in FIG. 4. As plunger 46 advances, wedge block 52 is moved from pegs 36d and 36a to free wheel 22 for rotation and face 60 of pusher block 58 bears against peg 36a, as seen in FIG. 7, to rotate wheel 22 in a counterclockwise direction as seen in FIG. 4. Plunger 46 is so constructed that when it meets shoulder 16 wheel 22 is advanced one frame 35 as seen through lens 40.

To lock wheel 22 in its advanced position, plunger 46 is released and spring 66 urges the plunger downwardly as seen in FIG. 5, moving wedge block 52 back into a position against two pegs 36c and 36f to lock wheel 22 and allowing pusher block 58 to ride over peg 36b as seen in FIG. 8 and come to rest between pegs 36b and 36c.

To remove carrier wheel 22 and insert another wheel it is merely necessary to depress plunger 46, which clears wedge block 52 from pegs 36, and pull the wheel laterally from cavity 118 against the action of detents 20, using indents 42 in walls l2 and M to obtain a grip on the wheel. When inserting a new wheel 22 the reverse action is carried out and in addition it may be necessary to rotate the wheel slightly to clear a peg 36 from lateral contact with pusher block 58.

I claim:

1. A picture viewer comprising:

a planar carrier wheel having a circular row of transparency frames and carrying a plurality of projections outstanding from the plane of the wheel and arranged in a ring, each frame having one projection associated therewith;

a housing having a cavity therein defined by a pair of opposed walls and by peripheral means constructed and arranged to retain said wheel loosely and releasably in said cavity for rotation about the axis of the wheel, the peripheral means and the opposed walls also defining a slot and the wheel being insertable into the housing cavity through the slot, said walls having a pair of aligned apertures therein. means whereby the frames on the wheel are selectively registrable individually with said apertures; plunger slidably mounted in the housing in the plane of the carrier wheel and projecting outwardly from the housing, the plunger being depressable from a position of rest into the housing against resilient compressive means;

a first arm and a second arm both projecting from the plunger into the housing cavity by means of at least one aperture, said arm lying in a plane parallel to the plane ofthe wheel, the first arm carrying wedge means constructed and arranged to lie between any two of the projections when the plunger is in said position of rest and removable therefrom when the plunger is depressed and returnable thereto when the plunger is released, the second arm being flexible in a direction normal to the wheel and substantially tangentially disposed in relation to the ring of projections, the second arm carrying pusher means constructed and arranged to bear against a different projection whereby the wheel is rotated when the plunger is depressed and the push'er means rides over the next succeeding projection when the plunger is released with the wedge means aligning anyone of said frames for viewing with the said aligned aperture.

2. A device as claimed in claim 1 in which the first arm lies in a plane normal to the wheel through a diameter thereof.

3. A device as claimed in claim l in which that wall of the housing adjacent the first and second arms carries a pair of parallel slots, the first arm and the second arm being parallel and slidable in said slots.

4. A device as claimed in claim l in which the plunger is spring loaded.

5. A device as claimed in claim l in which the pusher means has a bearing face remote from the plunger and a slide face tapering towards the second arm in the di rection of the plunger.

6. A device as claimed in claim 1 in which the wedge means is located adjacent that portion of the rim of the wheel remote from the plunger.

7. A device as claimed in claim 1 in which the peripheral means comprises a spacer separating the walls, the spacer having a substantially semicircular shoulder defining a cavity. the end portions of the shoulder carrying spring loaded detents constructed and arranged to retain the wheel removably in the cavity.

8. A device as claimed in claim 7 in which the shoulder of the spacer carries a plurality of transverse ridges spaced therealong. 

1. A picture viewer comprising: a planar carrier wheel having a circular row of transparency frames and carrying a plurality of projections outstanding from the plane of the wheel and arranged in a ring, each frame having one projection associated therewith; a housing having a cavity therein defined by a pair of opposed walls and by peripheral means constructed and arranged to retain said wheel loosely and releasably in said cavity for rotation about the axis of the wheel, the peripheral means and the opposed walls also defining a slot and the wheel being insertable into the housing cavity through the slot, said walls having a pair of aligned apertures therein, means whereby the frames on the wheel are selectively registrable individually with said apertures; a plunger slidably mounted in the housing in the plane of the carrier wheel and projecting outwardly from the housing, the plunger being depressable from a position of rest into the housing against resilient compressive means; a first arm and a second arm both projecting from the plunger into the housing cavity by means of at least one aperture, said arm lying in a plane parallel to the plane of the wheel, the first arm carrying wedge means constructed and arranged to lie between any two of the projections when the plunger is in said position of rest and removable therefrom when the plunger is depressed and returnable thereto when the plunger is released, the second arm being flexible in a direction normal to the wheel and substantially tangentially disposed in relation to the ring of projections, the second arm carrying pusher means constructed and arranged to bear against a different projection whereby the wheel is rotated when the plunger is depressed and the pusher means rides over the next succeeding projection when the plunger is released with the wedge means aligning anyone of said frames for viewing with the said aligned aperture.
 2. A device as claimed in claim 1 in which the first arm lies in a plane normal to the wheel through a diameter thereof.
 3. A device as claimed in claim 1 in which that wall of the housing adjacent the first and second arms carries a pair of parallel slots, the first arm and the second arm being parallel and slidable in said slots.
 4. A device as claimed in claim 1 in which the plunger is spring loaded.
 5. A device as claimed in claim 1 in which the pusher means has a bearing face remote from the plunger and a slide face tapering towards the second arm in the direction of the plunger.
 6. A device as claimed in claim 1 in which the wedge means is located adjacent that portion of the rim of the wheel remote from the plunger.
 7. A device as claimed in claim 1 in which the peripheral means comprises a spacer separating the walls, the spacer having a substantially semicircular shoulder defining a cavity, the end portions of the shoulder carrying spring loaded detents constructed and arranged to retain the wheel removably in the cavity.
 8. A device as claimed in claim 7 in which the shoulder of the spacer carries a plurality of transverse ridges spaced therealong. 